<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <a href="#footer">描点</a>
    <button id="btn"> 跳转到 footer位置</button>>
    <div class="footer"  id="footer"> </div>>
</body>
<script> 
  var btn = document.getElementById("btn");
  btn.onclick= function(){
      location.hash = "#footer";
      
  }

</script>
</html>